Pyrotechnic Igniting Agent

ABSTRACT

The present invention relates to a pyrotechnic igniting agent which contains basic salts of 5,5′-azotetrazole having the general empirical formula: M m+   n (C 2 N 10   2− ) p (CO 3   2− ) q (OH − ) r , wherein: M is an element of the 3rd to 12th group of the periodic table having an atomic number in the range from 21 to 80, (C 2 N 10   2− ) is azotetrazolate dianion having the structure (AA), m is the valence of the cation, n is an integer from 1 to 6, p is an integer from 1 to 4, q is an integer from 0 to 8, r is an integer from 0 to 4 and q+r≠0, wherein the proportion of the basic azotetrazolate component is 30 to 100 wt %, and 0 to 70 wt % of an additive or mixtures of a plurality of additives is contained.

The present invention relates to a pyrotechnic igniting agent.

In the context of the invention, pyrotechnic igniting agents are substances or substance mixtures which can have a pyrotechnic effect.

The present invention relates in particular to a pyrotechnic igniting agent which can be used in mechanical, electrical or optoelectrical ignition systems.

Document DE 102010025104 A1 discloses a 5,5′-azotetrazolate explosive which comprises an iron, cobalt, nickel, copper, cadmium or guanylurea salt of a 5,5′-azotetrazole or a mixture of at least one 5,5′ -azotetrazolate and at least one bis-tetrazolyltriazenate or at least one further metal salt or guanylurea salt of a 5,5′ -azotetrazole. The salts described therein are neutral, that is to say neither acidic nor basic. According to the document DE 102010025104 A1, zinc and chromium salts of 5,5′-azotetrazole are not storage-stable. Furthermore, the problem exists that pyrotechnic mixtures containing tetrazene are not sufficiently thermally stable since tetrazene decomposes at just 120° C.

One problem addressed by the present invention was that of providing a further pyrotechnic igniting agent. Another problem addressed by the present invention was that of providing a pyrotechnic igniting agent which can be used in mechanical, electrical or optoelectrical ignition systems.

According to the invention, this problem is surprisingly solved by the features of the main claim.

Further refinements of the invention are presented in the sub-claims.

There has surprisingly been discovered a pyrotechnic igniting agent which contains basic salts of 5,5′ -azotetrazole having the general empirical formula:

M^(m+) _(n)(C₂N₁₀ ²⁻)_(p)(CO₃ ²⁻)_(q)(OH⁻)_(r)

wherein:

M is an element of the 3rd to 12th group of the periodic table having an atomic number in the range from 21 to 80,

(C₂N₁₀ ²⁻) is azotetrazolate dianion having the structure

m is the valence of the cation,

n is an integer from 1 to 6,

p is an integer from 1 to 4,

q is an integer from 0 to 8,

r is an integer from 0 to 4 and q+r≠0,

wherein the proportion of the basic azotetrazolate component is 30 to 100 wt %, and 0 to 70 wt % of an additive or mixtures of a plurality of additives is contained. The novel basic azotetrazolate compounds according to the invention have deflagration temperatures in the range from 180° C. to 240° C., friction sensitivities of 0.1 N to 1.0 N and an impact sensitivity of 0.1 J to 0.5 J. The thermal stability of the basic azotetrazolate compounds according to the invention is given. Storage at 71° C. for 28 days did not lead to any decomposition of the basic azotetrazolate compound according to the invention, in particular the zinc compounds in this case.

Preferably, the pyrotechnic igniting agent is an agent which contains, as additive, 10 to 60 wt % of an oxidizing agent selected from one or more of the nitrates of the alkali and/or alkaline earth metals and/or of ammonium, the perchlorates of the alkali and/or alkaline earth metals and/or of ammonium, the peroxides of the alkali and/or alkaline earth metals and/or of zinc.

The pyrotechnic igniting agent particularly preferably contains, as additive, 0 to 10 wt % of a sensitizer, preferably tetrazene.

The pyrotechnic igniting agent according to the invention preferably contains, as additive, 0 to 20 wt % of a reducing agent selected from one or more of aluminum, antimony sulfide, calcium silicide, titanium, titanium hydride, boron, boron hydride, zirconium, zirconium hydride, silicon, graphite, activated carbon, carbon black or friction modifiers, preferably cullet.

The pyrotechnic igniting agent particularly preferably contains, as additive, 0.1 to 5 wt % of a binder selected from one or more of cellulose and derivatives thereof, polyvinyl butyrals, polynitropolyphenylene, polynitrophenyl ether, plexigum, polyvinyl acetate and copolymers.

With very particular preference, the pyrotechnic igniting agent contains

Zn²⁺ ₂(C₂N₁₀ ²⁻)(CO₃ ²⁻),

Zn²⁺ ₃(C₂N₁₀ ²⁻)₂(CO₃ ²⁻),

Zn²⁺ ₄(C₂N₁₀ ²⁻³)₂(CO₃ ²⁻)(OH⁻)₂,

Zn²⁺ ₂(C₂N₁₀ ²⁻)(OH⁻)2 and/or

Zn²⁺ ₃(C₂N₁₀ ²⁻)2(OH⁻)2.

The pyrotechnic igniting agents according to the invention are used in mechanical, electrical or optoelectrical ignition systems.

The following may be used as additives:

1. Oxidizing agents (individually or as mixtures) selected from the group consisting of:

-   -   nitrates of the alkali or alkaline earth metals or of ammonium,         such as sodium, potassium or ammonium nitrate, perchlorates of         the alkali or alkaline earth metals or of ammonium, peroxides of         the alkali or alkaline earth metals or of zinc.

2. Energy-rich aggregates (individually or as mixtures) of hexogen, octogen, nitrocellulose.

3. Reducing agents (individually or as mixtures) selected from the group consisting of:

aluminum, titanium, titanium hydride, boron, boron hydride, zirconium, zirconium hydride, silicon, graphite, activated carbon, carbon black.

4. Binders (individually or as mixtures) selected from the group consisting of:

cellulose and derivatives thereof, polyvinyl butyrals, polynitropolyphenylene, polynitrophenyl ether, plexigum, polyvinyl acetate, copolymers.

5. Combustion moderators, stabilizers and processing aids (individually or as mixtures) selected from the group consisting of:

-   -   zinc oxide, zinc carbonate, silicates, silica gels, silicic         acids, for example Aerosil (from the company Degussa), boron         nitride.

The substances are notable for being free of lead and barium, for having a high ignition power, short reaction times and suitable sensitivities. These properties make it possible to reduce the amount of explosive substances required for reliable ignition.

Table 1 shows the decomposition temperatures, friction sensitivities and impact sensitivities of selected examples. The friction sensitivities and impact sensitivities were measured using methods of the (Federal Institute for Materials Research and Testing) Bundesanstalt fur Materialforschung (BAM) specified in BAM report 142 (1987), while the decomposition temperatures were measured using differential scanning calorimetry (DSC) (from the company Mettler) at a heat-up rate of 10 K per minute.

Specifically, the present invention relates to:

-   -   a pyrotechnic igniting agent which contains basic salts of 5,5′         -azotetrazole having the general empirical formula:

M^(m+) _(n)(C₂N₁₀ ²⁻)_(p)(CO₃ ²⁻)_(q)(OH⁻)_(r)

-   -   wherein:     -   M is an element of the 3rd to 12th group of the periodic table         having an atomic number in the range from 21 to 80,     -   (C₂N₁₀ ²⁻) is azotetrazolate dianion having the structure

-   -   m is the valence of the cation,     -   n is an integer from 1 to 6,     -   p is an integer from 1 to 4,     -   q is an integer from 0 to 8,     -   r is an integer from 0 to 4 and q+r≠0,     -   wherein the proportion of the basic azotetrazolate component is         30 to 100 wt %, and 0 to 70 wt % of an additive or mixtures of a         plurality of additives is contained;     -   a pyrotechnic igniting agent which contains, as additive, 10 to         60 wt % of an oxidizing agent selected from one or more of the         nitrates of the alkali and/or alkaline earth metals and/or of         ammonium, the perchlorates of the alkali and/or alkaline earth         metals and/or of ammonium, the peroxides of the alkali and/or         alkaline earth metals and/or of zinc;     -   a pyrotechnic igniting agent which contains, as additive, 0 to         10 wt % of a sensitizer, preferably tetrazene;     -   a pyrotechnic igniting agent which contains, as additive, 0 to         20 wt % of a reducing agent selected from one or more of         aluminum, antimony sulfide, calcium silicide, titanium, titanium         hydride, boron, boron hydride, zirconium, zirconium hydride,         silicon, graphite, activated carbon, carbon black or friction         modifiers, preferably cullet;     -   a pyrotechnic igniting agent which contains, as additive, 0.1 to         5 wt % of a binder selected from one or more of cellulose and         derivatives thereof, polyvinyl butyrals, polynitropolyphenylene,         polynitrophenyl ether, plexigum, polyvinyl acetate and         copolymers;     -   a pyrotechnic igniting agent which contains Zn²⁺ ₂(C₂N₁₀ ²⁻)(CO₃         ²⁻);     -   a pyrotechnic igniting agent which contains Zn²⁺ ₃(C₂N₁₀         ²⁻)₂(CO₃ ²⁻);     -   a pyrotechnic igniting agent which contains Zn²⁺ ₄(C₂N₁₀         ²⁻)₂(CO₃ ²)(OH⁻)₂;     -   a pyrotechnic igniting agent which contains Zn²⁺ ₂(C₂N₁₀         ²⁻)₂(OH⁻)₂;     -   a pyrotechnic igniting agent which contains Zn²⁺ ₃(C₂N₁₀         ²⁻)₂(OH⁻)₂;     -   the use of a pyrotechnic igniting agent in mechanical,         electrical or optoelectrical ignition systems.

The invention will be explained in greater detail by the following examples, without being limited thereto:

Table 1 shows the compositions of 5 different basic salts of 5,5′-azotetrazole.

TABLE 1 Compositions, deflagration temperatures, friction sensitivities and impact sensitivities of selected basic salts of 5,5′-azotetrazole. T_(deflag.) ^([a]) F_(friction) ^([b]) E_(impact) ^([c]) No. Empirical formula in ° C. in N in J 1 Zn²⁺ ₂(C₂N₁₀ ²⁻)(CO₃ ²⁻) 227 0.7 0.3 2 Zn²⁺ ₃(C₂N₁₀ ²⁻)₂(CO₃ ²⁻) 223 0.5 0.1 3 Zn²⁺ ₄(C₂N₁₀ ²⁻)₂(CO₃ ²⁻) 215 0.7 0.3 4 Zn²⁺ ₂(C₂N₁₀ ²⁻)(OH⁻)2 210 0.5 0.2 5 Zn²⁺ ₃(C₂N₁₀ ²⁻)₂(OH⁻)₂ 207 0.3 0.1 ^([a])deflagration temperature; ^([b])friction sensitivity; ^([c])impact sensitivity. 

1. A pyrotechnic igniting agent, characterized in that it contains basic salts of 5,5′-azotetrazole having the general empirical formula: M^(m+)(C₂N₁₀ ²⁻)_(p)(CO₃ ²⁻)_(q)(OH⁻)_(r) wherein: M is an element of the 3rd to 12th group of the periodic table having an atomic number in the range from 21 to 80, (C₂N₁₀ ²⁻) is azotetrazolate dianion having the structure

m is the valence of the cation, n is an integer from 1 to 6, p is an integer from 1 to 4, q is an integer from 0 to 8, r is an integer from 0 to 4 and q+r≠0, wherein the proportion of the basic azotetrazolate component is 30 to 100 wt %, and 0 to 70 wt % of an additive or mixtures of a plurality of additives is contained.
 2. The pyrotechnic igniting agent according to claim 1, characterized in that it contains, as additive, 10 to 60 wt % of an oxidizing agent selected from one or more of the nitrates of the alkali and/or alkaline earth metals and/or of ammonium, the perchlorates of the alkali and/or alkaline earth metals and/or of ammonium, the peroxides of the alkali and/or alkaline earth metals and/or of zinc.
 3. The pyrotechnic igniting agent according to claim 1, characterized in that it contains, as additive, 0 to 10 wt % of a sensitizer, preferably tetrazene.
 4. The pyrotechnic igniting agent according to claim 1, characterized in that it contains, as additive, 0 to 20 wt % of a reducing agent selected from one or more of aluminum, antimony sulfide, calcium silicide, titanium, titanium hydride, boron, boron hydride, zirconium, zirconium hydride, silicon, graphite, activated carbon, carbon black or friction modifiers, preferably cullet.
 5. The pyrotechnic igniting agent according to claim 1, characterized in that it contains, as additive, 0.1 to 5 wt % of a binder selected from one or more of cellulose and derivatives thereof, polyvinyl butyrals, polynitropolyphenylene, polynitrophenyl ether, plexigum, polyvinyl acetate and copolymers.
 6. The pyrotechnic igniting agent according to claim 1, characterized in that it contains Zn²⁺ ₂(C₂N₁₀ ²⁻)(CO₃ ²⁻).
 7. The pyrotechnic igniting agent according to claim 1, characterized in that it contains Zn²⁺ ₃(C₂N₁₀ ²⁻)₂(CO₃ ²⁻).
 8. The pyrotechnic igniting agent according to claim 1, characterized in that it contains Zn²⁺ ₄(C₂N₁₀ ²⁻)₂(CO₃ ²⁻)(OH⁻)₂.
 9. The pyrotechnic igniting agent according to claim 1, characterized in that it contains Zn²⁺ ₂(C₂N₁₀ ²⁻)(OH⁻)₂.
 10. The pyrotechnic igniting agent according to claim 1, characterized in that it contains Zn²⁺ ₃(C₂N₁₀ ²⁻)₂(OH⁻)₂.
 11. The use of a pyrotechnic igniting agent according to claim 1 in mechanical, electrical or optoelectrical ignition systems. 